/*
 * Copyright 2007 Brian Watkins
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package bw.util;

import java.util.*;

public class BlockingWorkerPool extends WorkerPool implements WorkerListener
{
    private BlockingQue _available = new BlockingQue();
    private HashSet _working = new HashSet();

    //A WorkerPool that blocks until a Worker is free

    public BlockingWorkerPool ( String name, int size )
    {
        super( name, size );

        Iterator workers = _workers.iterator();
        while ( workers.hasNext() )
        {
            Worker worker = (Worker) workers.next();
            worker.setListener( this );
            _available.add( worker );
        }
    }

    protected Worker getAvailableWorker ()
    {        
        //this will block here until a worker become available
        Worker worker = (Worker) _available.remove();

        _working.add( worker );

        return worker;
    }

    public void workCompleted ( Worker worker, Runnable work )
    {
        _working.remove( worker );
        _available.add( worker );
    }
}